s sc=##class(%ZEN.Auxiliary.jsonSQLProvider).%WriteJSONFromSQL("json","SELECT Name FROM Sample.Person")

While the idea is essentially the same (REST API) - each cloud provider uses slightly different calls and signatures to access data in the storage bucket. So unlikely you'll find a single example that works for every provider.

IRIS External Table  contains Object Script implementation of the storage bucket adapters for AWS, Azure and Google Cloud.

https://github.com/intersystems-community/IRIS-ExternalTable#using-cloud-adapters-outside-of-externaltable - would give you an idea on how to use adapters directly.